130 MR. C. W. ANDREWS AND OTHERS ON THE [Feb. 20, 



their shape is subspherical, elongated or pyriforrn, and they vary 

 in size from 1 to 5 c.c. in length or diameter, and in colour from 

 yellow to dark brown. The alcohol specimens are much skrunken 

 and corrugated, the surface being marked with polygonal or elon- 

 gated depressions ("wabige vertiefungen," 0. Schmidt) with pig- 

 mented stellate markings. The specimen in formol, which was 

 unfortunately transferred to alcohol, was bluish-black and quite 

 smooth. 



On drying, the surface has a distinctly gritty appearance, caused 

 by the shrinking of the dermal membrane on the foreign particles 

 beneath. 



The foreign bodies (fine sand-grains, sponge-spicules) form a 

 fairly-well defined layer in the cortex and just beneath the 

 dermal membrane ; in one specimen spicules projected beyond the 

 surface at right angles. There are no foreign bodies scattered in 

 the interior of the body, differing in this respect from the speci- 

 mens from Algiers described by O. Schmidt. 



Distribution. Mediterranean ; Atlantic ; Christmas Island. 



Chondrilla nuda Lendenfeld. 



1867. Chondrilla nuda Lendenfeld (9. p. 105, pl.x. figs. 69-71). 



One small specimen of this species occurs in the form of a 

 rounded bilobed mass 8x9x4 mm. in size, growing on Chondroma 

 plebeja. 



The surface is bluish-black and smooth, aud shows under a 

 lens a faint whitish reticulate pattern. The larger lobe has two 

 minute raised oscules '3 mm. in diameter. The cortical layer 

 includes columns of large granular pigmented cells, as in the 

 specimen from Zanzibar. 



The spicules are slightly larger than in Lendenfeld's specimens. 

 The oxyasters, 30 f± in diameter, possess 8 sharp spines usually 

 slightly curved. The spherasters, 25 fj. in diameter, possess 25- 

 30 sharp-pointed pyramidal prickles. In the Zanzibar specimens 

 the oxyasters are 22-30 yu, and the spherasters only 10-12 u in 

 diameter. 



Distribution. Zanzibar ; Christmas Island. 



Sidonops picteti Topsent. 



1897. Sydonops picteti Topsent (18. p. 431, pi. xviii. fig. 2). 



1898. Sidonops picteti Lindgren (10. p. 349, pi. xviii. fig. 17, 

 pi. xx. fig. 6). 



There are four small specimens, the largest of which is 5 c.c. by 

 2 c.c. in area and 1*5 c.c. in thickness. Several small spherical buds 

 about 2 mm. in diameter are lightly but closely attached by bundles 

 of oxeote spicules. "When a bud is detached, a shallow circular 

 depression remains, the sterrastral crust here being thin and 

 biconcave in section. 



The slender cortical oxeas and the oscular palisade of spicules 

 described by Lindgren are present. 



Distribution. Amboina ; Java ; Christmas Island. 



